by William M. Welch, USA TODAY

by William M. Welch, USA TODAY

If her jailhouse admissions are true, Miranda Barbour's name could be added to a list of women who have become notorious as serial killers.

While greatly outnumbered by males who have committed multiple killings, cases of females who kill repeatedly do occur, and women have been executed as serial killers.

"We've always had female serial killers,'' says Eric Hickey, a criminal psychologist and dean of the California School of Forensic Studies in California. "But they make up just about 15% or 16% of the serial murderer population we've seen over the years.''

Barbour, 19, is charged in Pennsylvania along with her husband in the killing of a man they met through a Craigslist online listing, and in an interview with The Daily Item in Sunbury said she has killed more than 20 others around the country.

Attorneys for Barbour and her husband, Elytte Barbour, 22, have both sought psychiatric evaluations for their clients. Police say they are looking into the allegations and the FBI has offered assistance. She is accused of stabbing Troy LaFerrara 20 times as her husband held a cord around the victim's neck in a car.

Hickey, author of Serial Murderers and Their Victims, said that the involvement of a male is common among females that kill outside their family with violence. Women killing alone tend to fall more into the "black widow" category, killing a husband or other family member or friend through poison or other means, while women who commit violence often are directed, manipulated or accompanied by a man, he said.

"Usually a male is the leader,'' he said. "I suspect he's probably the brains behind it or the one who wanted to initiate it.''

Barbour said she was sexually abused as a child and joined a satanic cult in Alaska when she was 13. Soon after, she said, the cult leader helped her pull the trigger when she killed a man she said owed the cult leader money. "And then from there I just continued to kill," she told the newspaper.

While her claims have yet to be substantiated, Hickey said women who confess to such crimes aren't likely to lie for the sake of notoriety.

"Usually women don't tend to confess like that unless they're telling the truth,'' she said. "They're not into the notoriety as much as the men are.''

Among the most notorious:

-- Aileen Wuornos was executed in Florida in 2002 at 46 after confessing to killing six men she said she met while working as a prostitute. Each of the victims was struck by multiple bullets. Her case inspired several books and a 2003 Hollywood film, Monster. Charlize Theron won an Academy Award for playing the Wuornos role.

-- North Carolina executed Margie Velma Barfield in 1984 at age 52, the first woman to be executed after the 1976 resumption of capital punishment in the United States. She was convicted of one murder, spiking a boyfriend's drinks with rat poison, and confessed to six deaths, including her own mother. Prosecutors said she had taken money from victims, forged checks or taken out loans in their names to pay for a prescription drug addiction.

-- Gwendolyn Graham, 50, is serving a life prison sentence after being convicted of killing five elderly women in a Michigan nursing home where she worked as nurse's aides. The killings were part of a lovers' pact with another woman, prosecutors contended.